Resealing fuel tank

[Chris Hoefly]

Any resources available, diagrams or videos, on how to open fuel tank access panels. And tips on sealing tanks. 
thanks 

[1967 427]

Tip of the day.  Take it to a shop.

All kidding aside there are some things worth having someone else do.

[N201MKTurbo]

35 minutes ago, Chris Hoefly said:

Any resources available, diagrams or videos, on how to open fuel tank access panels. And tips on sealing tanks. 
thanks 

https://www.aircraftspruce.com/catalog/topages/skinWedge2.php
 

This is the tool to use to get the panels off. It won’t scratch the panels. Work it in pointing away from the center of the panel, then move an inch to the side and do it again. When you are about half way around the panel the long way, you can pry on the panel and it will separate.

It is a good idea to put aluminum tape over the panels before you start to do this. Just push the skin wedge through the tape.

Edited February 6, 2021 by N201MKTurbo

[N201MKTurbo]

Don Maxwell used to have an article about how to fix tanks. It seems he has taken it down.

[Wes]

Find someone who specializes in that....you'll be glad you did. Some things need to be done by the people that do what they do. Not saying it can't be done, just saying that if you like yourself even a little bit, you wouldn't put yourself through it. Had mine done by Paul at Weep-no-more. Glad I did. Not cheap to have done, but when it's done right, problems are solved. Only my opinion....Good luck.

[LunkenPilot]

Weep-no-more was worth the trip for me. Done a dew years back. Zero issues since. 

[cctsurf]

Just now, LunkenPilot said:

Weep-no-more was worth the trip for me. Done a dew years back. Zero issues since. 

You beat me to it.  I was going to post their web page.  I know people who have fought for years trying to seal especially small leaks in their tanks.  One trip to Willmar and it was dry.  My plane required new doughnuts before they would guarantee it.  13 years later she's dry as a bone.

http://www.weepnomorellc.com/

[0TreeLemur]

Had mine done by Wetwingologists in Fort Lauderdale, FL.   Still good with no leaks after 2 years.   Winter is a nice time to take a trip to Florida.

[carusoam]

9 hours ago, Chris Hoefly said:

Any resources available, diagrams or videos, on how to open fuel tank access panels. And tips on sealing tanks. 
thanks 

Chris, when you get a chance...

Find the search function...

One of the coolest projects was completed by a Young Mooney pilot...

He completely stripped and resealed is M20C’s fuel tanks... find Alex / Raptor’s thread... lots of real good info.... with pics...

On the other hand... there are at least four resources that will do the entire job for you.... find the one closest to you...

What else can we answer for you..?

If you supply a touch more detail with your questions... you will get infinitely more detail in the answers...

Have no fear...  if you ask too many questions... you will run out of hours in the day...  

What are you trying to find out?

Best regards,

-a-

[RobertGary1]

Are you taking a nuclear strip and reseal or a routine patch?

The bible

https://web.archive.org/web/20190103195252/http://donmaxwell.com/fuel-tank-repairs-how-we-fix-them/

 

 

 

[EricJ]

9 minutes ago, RobertGary1 said:

Are you taking a nuclear strip and reseal or a routine patch?

The bible

https://web.archive.org/web/20190103195252/http://donmaxwell.com/fuel-tank-repairs-how-we-fix-them/

Thank god for the wayback machine.

[Immelman]

I used pick to remove the sealant that fills the little channel between wing skin and top of access panel. Then a putty knife. Its not that hard to remove. But I say that after having done it a few times. Go slow. Patience is a virtue.

The panel under the wing walk is a lot more difficult due to fuel tank sealant holding it in (Because it is stepped on) vs access panel sealant.

The cleaning and prep work to re-install the panel properly is substantial.

It is easy to have the knife go too far and nick some sealant in the tank, past the edge of the panel. be careful of that.

Edited February 7, 2021 by Immelman

[Prior owner]

10 hours ago, N201MKTurbo said:

Don Maxwell used to have an article about how to fix tanks. It seems he has taken it down.

Yes, all his articles are gone from his site now... at least I haven’t been able to find them. I did save a few though.

[N201MKTurbo]

There are two type of people on here. 
 

Those that want to master a new skill and those that don’t don’t value those things.

[SSimpson77]

Chris, I just finished up a patch on my C. Not all that bad really. I wouldn’t suggest the tool above, it’s too thick and could bend the lip. I bought a bunch of different kinds of scrapers and plastic molding tools from harbor freight and nothing worked. Here’s what I found was best:

#1. Tell your mechanic what your doing. You’ll need his support when you think your doing it wrong and him to approve of the work. 
#2. drain tank- even pulling the sump-drain leaves about 2 cups of 100LL in tank. I recall a quote my dad told me when I was young- a cup of gas vaporized is as dangerous as 6 sticks of dynamite! 
#3 Apply heat to panels-remember dynamite. So purge the tanks a few times with water. You’ll get really good at this for the clean up and test and cleanup stage. 
#4 kitchen butter knife-a very thin one works best. Literally I tried all the other scrapers and pry plastic bars. With the knife it was done in 5 minutes. Thin knife. I tried slipping feeler gauges and working them around. Just cut my fingers to heck and bent my .010” gauge. 
As like all others said, put some tape on inspection cover to protect the edges.

Finally find the article from don maxwell about clear plexiglass and pulling a vacuum through vent. Instantly comes up where your leak is. I found my leak, the Inside top corner where the aluminum angle joins (joggles) and spent two hours cleaning and applying chem seal. Then vacuum test, clean, clean clean. 

I forgot, put a glove over pick up tube to keep stuff out. 

I couldn’t find anymore MEK, but the substitute stuff works okay. 

Good luck. It was truly about 4 hours of work, but three days due to cleaning, application, cure times, test, cure times. The bottom picture is “because I was inverted”

[Bob E]

On 2/6/2021 at 10:13 PM, N201MKTurbo said:

There are two type of people on here. 
 

Those that want to master a new skill and those that don’t don’t value those things.

I suggest there's a third type too:  Those who definitely value mastering new skills - any pilot fits that description? - but who either (for reasons of job, family, or whatever) don't have the time to master and perform this particular skill, or who know their own limits when it comes to do-it-yourself work on an aircraft and don't wish to exceed them.

Regarding DIY I've posted a number of items here on MS that seem have been useful to others. With respect to sealing fuel tanks, though, I fit into both categories of that third type.  Even if I had the time to devote to such a project, I wouldn't trust my own ability to seal fuel tanks without screwing up the fuel senders or who knows what else, and to do it properly.

[N201MKTurbo]

3 hours ago, SSimpson77 said:

Chris, I just finished up a patch on my C. Not all that bad really. I wouldn’t suggest the tool above, it’s too thick and could bend the lip. I bought a bunch of different kinds of scrapers and plastic molding tools from harbor freight and nothing worked. Here’s what I found was best:

#1. Tell your mechanic what your doing. You’ll need his support when you think your doing it wrong and him to approve of the work. 
#2. drain tank- even pulling the sump-drain leaves about 2 cups of 100LL in tank. I recall a quote my dad told me when I was young- a cup of gas vaporized is as dangerous as 6 sticks of dynamite! 
#3 Apply heat to panels-remember dynamite. So purge the tanks a few times with water. You’ll get really good at this for the clean up and test and cleanup stage. 
#4 kitchen butter knife-a very thin one works best. Literally I tried all the other scrapers and pry plastic bars. With the knife it was done in 5 minutes. Thin knife. I tried slipping feeler gauges and working them around. Just cut my fingers to heck and bent my .010” gauge. 
As like all others said, put some tape on inspection cover to protect the edges.

Finally find the article from don maxwell about clear plexiglass and pulling a vacuum through vent. Instantly comes up where your leak is. I found my leak, the Inside top corner where the aluminum angle joins (joggles) and spent two hours cleaning and applying chem seal. Then vacuum test, clean, clean clean. 

I forgot, put a glove over pick up tube to keep stuff out. 

I couldn’t find anymore MEK, but the substitute stuff works okay. 

Good luck. It was truly about 4 hours of work, but three days due to cleaning, application, cure times, test, cure times. The bottom picture is “because I was inverted”

BTW, the tool I mentioned above works far better than anything you mentioned. Have you tried it? 

[N201MKTurbo]

22 minutes ago, Bob E said:

I suggest there's a third type too:  Those who definitely value mastering new skills - any pilot fits that description? - but who either (for reasons of job, family, or whatever) don't have the time to master and perform this particular skill, or who know their own limits when it comes to do-it-yourself work on an aircraft and don't wish to exceed them.

Regarding DIY I've posted a number of items here on MS that seem have been useful to others. With respect to sealing fuel tanks, though, I fit into both categories of that third type.  Even if I had the time to devote to such a project, I wouldn't trust my own ability to seal fuel tanks without screwing up the fuel senders or who knows what else, and to do it properly.

You are correct, I was a bit harsh. There were times I would have paid someone to do it, but the best I could find was 6 months  out. I can’t wait that long. 
 

I have found that most certified mechanics don’t have any more skills than the average airplane owner when it comes to these tank repairs. I hate the term “patch” BTW,  there is nothing in the maintenance manual about patching the tank, it tells you how to repair a sealant failure. Most of what people find in their tanks are un-approved repairs done by certified mechanics. I hope everyone on here realize that these repairs must be done under the supervision of a licensed mechanic, there is no way these repairs fall under owner maintenance. 
 

@Eric J how much time did they spend on wet wing tank repair at the school?

[N201MKTurbo]

BTW , I was having a hard time finding MEK. I was at the local paint store and asked them if they had MEK. They said I think so, they looked around and found a 5 gallon can and sold it to me for $90. I’m set for life now...

[EricJ]

18 hours ago, N201MKTurbo said:

 

@Eric J how much time did they spend on wet wing tank repair at the school?

Not a lot, and mostly in the context of repairing tanks on jets/airliners.   There was probably more time spent on safety considerations for an actual tank diver, i.e., the guy that gets sent inside an airliner tank to do the repair, than on actually doing repairs.   None of that applies to fixing a Mooney tank, since you don't actually need to go inside. 

[Nokomis449]

21 hours ago, N201MKTurbo said:

BTW , I was having a hard time finding MEK. I was at the local paint store and asked them if they had MEK. They said I think so, they looked around and found a 5 gallon can and sold it to me for $90. I’m set for life now...

A friend of mine is a Captain that pushes hazardous chemicals up the Mississippi between the refineries in Baton Rouge and Chicago.  One day I mentioned MEK to him, and he said "How much do you need?  I've got a whole barge full of it right now". 

Talk about being set FOR LIFE!!!

[carusoam]

Great pics SS!

And Dad’s insight is pretty good too...

Best regards,

-a-

[Bob E]

On 2/7/2021 at 11:45 PM, N201MKTurbo said:

BTW , I was having a hard time finding MEK. I was at the local paint store and asked them if they had MEK. They said I think so, they looked around and found a 5 gallon can and sold it to me for $90. I’m set for life now...

Wow!  MEK is hard to find; it's a standing item on my wish list.  All I can find is the substitute.  Next time I'm in AZ I'm bringing an empty cannister and maybe some top-grade Hennessy and we'll see if I can talk you into parting with a little of it.

[N201MKTurbo]

5 hours ago, Bob E said:

Wow!  MEK is hard to find; it's a standing item on my wish list.  All I can find is the substitute.  Next time I'm in AZ I'm bringing an empty cannister and maybe some top-grade Hennessy and we'll see if I can talk you into parting with a little of it.

No problem .

I found out you can get it from Spruce for about twice what I paid for it, 5 times if you buy a quart plus shipping.

https://www.aircraftspruce.com/catalog/cspages/polyfibermek.php?clickkey=5201

 

Edited February 9, 2021 by N201MKTurbo

[Brian Coate]

6 hours ago, Bob E said:

Wow!  MEK is hard to find; it's a standing item on my wish list.  All I can find is the substitute.  Next time I'm in AZ I'm bringing an empty cannister and maybe some top-grade Hennessy and we'll see if I can talk you into parting with a little of it.

I usually get it at Lowe's.   I have never had trouble getting it.